“If microbial life were to disappear, that would be it—instant death for the planet."
- Carl Woese, Ph.D., American microbiologist and biophysicist
“To declare war on ninety-nine percent of bacteria when less than one percent of them threaten health makes no sense. Many of the bacteria we’re killing are our protectors.”
- Sandor Katz, American food writer
At the beginning of the COVID-19 pandemic, many people engaged in the obsessive and excessive cleaning of all surfaces—even cardboard. The Atlantic’s Derreck Thompson dubbed these behaviors “hygiene theater.” In my May 5, 2021 Germ Gems post, “The ‘Hygiene Hypothesis’ and Why You Should Care,” I suggested that the era of “hygiene theater” had come to an end. Apparently, I was wrong. In the July 7, 2022 article in The Atlantic “How Are We Possibly Still Disinfecting Things?” science writer Yasmin Tayag states, “[S]igns of flaunting cleanliness are still all over the place,” and “America can’t quit hygiene theater.” In this week’s Germ Gems post, I revisit the topic of health and hygiene and provide additional perspective on the microbiome of the environment.
What is “hygiene?” Derived from the French (with Greek and Latin roots), the word hygiene means “art of health” and is a series of practices done to preserve health. Some hygiene practices have an ancient evolutionary history. For example, ancient Egyptians used many healthy hygiene habits such as daily bathing and shaving their heads to prevent lice. In ancient India, elaborate practices for personal hygiene were carried out, including three daily baths. These ancient civilizations may have had various reasons for practicing the “art” of hygiene, but the scientific underpinning for these practices was not provided until the late 19th Century.
In the late 1800s, German physician Robert Koch proved that the anthrax bacterium (Bacillus anthracis) causes anthrax, and the French chemist Louis Pasteur provided the principles of vaccination, microbial fermentation, and pasteurization. Their discoveries formed the basis of the “Germ Theory of Disease.” (Celebrating its 150th Anniversary this year, Popular Science has made available from its archives the amazing treatise by H. Gradle, M.D., “The Germ-Theory of Disease” published in 1883.) Once bacteria were determined to cause an array of serious diseases, germs became “our enemies.”
What is hygiene hysteria? Not surprisingly, the COVID-19 pandemic stoked an enormous interest in hygiene. As you likely recall, at the outset of the pandemic, it was not clear to scientists how SARS-CoV-2, the coronavirus that causes COVID-19, is transmitted. Fear took hold. As Yasmin Tayag says in her Atlantic article, “As I unpacked my groceries, I was gripped by fear. If I don’t Lysol the living daylights out of this cardboard, I wondered, will I die?”
As we learned more about the science behind how one catches the virus (or rather, how the virus catches us), that is, through aerosols (tiny particles) expelled from the human respiratory tract, we were able to make informed decisions about hygiene protocols. We learned to observe social distancing, wear masks, and sanitize our hands. At this juncture, most people are no longer disinfecting their groceries. But, other signs of flaunting cleanliness persist, including sanitizing credit-card readers, using QR-codes instead of paper menus, and wiping down checkout counters at grocery stores. These behaviors, i.e., “hygiene theater,” are more performative than useful at stopping the spread of SARS-CoV-2. What you really want to know is what a restaurant, school, business, etc. has done to assure proper air filtration. (Vigorous handwashing remains a very good idea, mainly to prevent diseases caused by pathogens transmitted by hands such as norovirus, cases of which have diminished during the COVID-19 pandemic.)
The good germs. As I’ve pointed out previously, the human microbiome (defined as the microbes that share our body surfaces) plays an essential role in many aspects of human health. For example, the roughly 40 trillion bacteria in the gut microbiome contribute to digestion of foods, train the immune system, and via the so-called “gut-brain axis” shape our emotions.
The bacteria found in the five human microbiomes (gut, skin, mouth, lungs, and vagina), however, are an infinitesimally small fraction of the 5 times 10 to the 30th bacteria found on Earth. As was discussed in an article in Smithsonian Voices on April 26, 2022, “Meet the Small but Mighty Microbiome,” microbiomes are everywhere, not just in animals but in soil, water, and plants. In fact, one of the most rapidly growing fields in microbiology, called the “microbiology of the built environment,” explores how microbes in building materials influence human health.
What’s the harm of hygiene overkill? The potential adverse effects of overdoing hygienic measures on the friendly germs in the human and other microbiomes are difficult to assess, and an argument based on protecting these protectors is hard to sell. But one concern that’s been voiced by several authors is: are we raising little germaphobes?
Germaphobia, also known as mysophobia, is a pathological fear of contamination and germs. William Hammond coined the term in 1879 when describing a case of obsessive-compulsive disorder (OCD) exhibited by repeatedly washing one’s hands. Like other OCDs, germaphobia is a serious medical condition for which there is treatment. The disorder is not uncommon, afflicting about 5% of the American population. Perhaps ending “hygiene theater” is one way to foster its prevention.